1. Field of the Invention
The present invention relates to a valve operating system for a multi-cylinder internal combustion engine, and particularly, to a valve operating system for a multi-cylinder internal combustion engine, in which in a desired cylinder among a plurality of cylinders, both of a pair of intake valves can be closed and stopped.
2. Description of the Prior Art
A valve operating system capable of closing and stopping both of a pair of intake valves is conventionally known, for example, from Japanese Utility Model Publication No. 24888/90 and Japanese Patent Publication No. 50284/90.
In the known valve operating system, both of the pair of intake valves are operatively connected to a single driving rocker arm and opened and closed with the same operational characteristic. In a low speed operational range of the engine, both of the intake valves are opened and closed and hence, there is a failure to form a swirl in the combustion chamber to provide a stable combustion.